diff --git a/src/app/InterfaceSettings.tsx b/src/app/InterfaceSettings.tsx
index 37134f3..860f96c 100644
--- a/src/app/InterfaceSettings.tsx
+++ b/src/app/InterfaceSettings.tsx
@@ -220,12 +220,12 @@ export function InterfaceSettings({ snapshot }: { snapshot: ControlSnapshot }):
 
         <SwitchCard
           overline="MOTION"
-          title="Animation"
-          blurb="Disable interface transitions and animated state changes."
-          label="Reduce motion"
+          title="Animations"
+          blurb="Enable interface transitions and animated state changes."
+          label="Enable animations"
           id="interface-reduced-motion"
-          checked={preferences.reducedMotion}
-          onChange={set("reducedMotion")}
+          checked={!preferences.reducedMotion}
+          onChange={(next) => set("reducedMotion")(!next)}
         />
         <SwitchCard
           overline="WRITES"
diff --git a/src/control.css b/src/control.css
index 8b650a6..ea7d5ee 100644
--- a/src/control.css
+++ b/src/control.css
@@ -892,9 +892,10 @@ nav { display: grid; gap: .3rem; margin-top: 1.4rem; }
   .control-shell.is-empty .empty-state > p:not(.overline) { margin-top: 1rem; }
 }
 
-@media (prefers-reduced-motion: reduce) {
-  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
-}
+/* NOTE: no global prefers-reduced-motion override here on purpose. The
+   site setting (.reduce-interface-motion above) is the single source of
+   truth and it is initialized from the OS preference, so an explicit
+   "Enable animations" choice is never overridden by the OS. */
 
 /* Monochrome workspace — selected from the concept-18 exploration. */
 body { height: 100vh; overflow: hidden; }
@@ -2409,10 +2410,8 @@ body { height: 100vh; overflow: hidden; }
   from { max-height: 5rem; opacity: 1; }
   to { max-height: 0; padding-block: 0; opacity: 0; transform: translateY(-.2rem); }
 }
-@media (prefers-reduced-motion: reduce) {
-  .toast { animation: none; }
-  .toast.is-leaving { animation-duration: .01s; }
-}
+.reduce-interface-motion .toast { animation: none; }
+.reduce-interface-motion .toast.is-leaving { animation-duration: .01s; }
 
 .control-shell[data-interface-theme="liquid-glass"] .toast-stack {
   border-color: var(--glass-border-elevated);
diff --git a/src/interface-preferences.ts b/src/interface-preferences.ts
index a605ac9..6b71e2b 100644
--- a/src/interface-preferences.ts
+++ b/src/interface-preferences.ts
@@ -53,20 +53,34 @@ function clampGlassIntensity(value: unknown): number {
   return Math.min(100, Math.max(0, Math.round(number)));
 }
 
+/** OS-level preference. Used only as the initial default so an explicit
+    site choice always wins over the system setting. */
+export function systemPrefersReducedMotion(): boolean {
+  try {
+    if (typeof window !== "undefined" && typeof window.matchMedia === "function") {
+      return window.matchMedia("(prefers-reduced-motion: reduce)").matches;
+    }
+  } catch {
+    // Ignore and fall through to the animated default below.
+  }
+  return false;
+}
+
 export function loadInterfacePreferences(storage: Storage): InterfacePreferences {
   try {
     const saved = JSON.parse(storage.getItem(STORAGE_KEY) ?? "{}") as Partial<InterfacePreferences>;
     return {
       theme: THEMES.includes(saved.theme as InterfaceTheme) ? saved.theme as InterfaceTheme : "Mono",
       colorMode: saved.colorMode === "Light" || saved.colorMode === "Dark" ? saved.colorMode : "System",
-      reducedMotion: saved.reducedMotion === true,
+      reducedMotion:
+        typeof saved.reducedMotion === "boolean" ? saved.reducedMotion : systemPrefersReducedMotion(),
       expandSections: saved.expandSections === true,
       showExperimental: saved.showExperimental !== false,
       instantFlash: saved.instantFlash === true,
       glassIntensity: clampGlassIntensity(saved.glassIntensity),
     };
   } catch {
-    return { ...DEFAULT_INTERFACE_PREFERENCES };
+    return { ...DEFAULT_INTERFACE_PREFERENCES, reducedMotion: systemPrefersReducedMotion() };
   }
 }